Bevel locking system for a sliding compound miter saw

ABSTRACT

A power tool includes a table. A shaft is disposed on the table and has an axis. A support housing supporting a motor and a working tool driven by the motor is disposed on the shaft adjacent to the table. The support housing is axially movable along the shaft and being laterally pivotable about an axis of rotation. A locking mechanism is further provided for locking the support housing at a predetermined lateral position, wherein the locking mechanism may include a handle disposed on the shaft, the handle being rotatable in two directions with respect to the table, such that, upon rotation of the handle in both directions from a neutral position, the handle urges the support housing into contact with the table. The shaft may be rotatable relative to the table. The locking mechanism may further include a first camming surface disposed on the table and a second camming surface disposed on the shaft and engaging the first camming surface. Alternatively, the shaft may include a first surface having a first thread disposed thereon in a first orientation, and a second surface having a second thread disposed thereon in a second orientation, the first and second thread intersect forming a V-shaped thread. The table may then include at least one protrusion slidable along the first and second threads.

This application is a continuation of U.S. Ser. No. 09/481,272, filedJan. 11, 2000, now U.S. Pat. No. 6,631,661, which is a continuation ofU.S. Ser. No. 09/057,708, filed Apr. 9, 1998, now U.S. Pat. No.6,032,562, which is a continuation-in-part of U.S. Ser. No. 08/761,730,filed Dec. 5, 1996, now U.S. Pat. No. 5,870,938; which claims thebenefit of U.S. Provisional Application No. 60/008,512, filed Dec. 12,1995, now abandoned.

FIELD OF THE INVENTION

The present invention relates to compound miter saws or other poweroperated equipment or machinery utilizing a cutter for performingworking operations on a workpiece. More particularly, the presentinvention relates to improvements in the bevel lock mechanism for thebevel adjustment for such power operated equipment.

BACKGROUND OF THE INVENTION

Saws and other apparatuses designed for cutting or performing otherworking operations on a workpiece typically require adjustmentmechanisms for moving the saw blade or cutting tool into an angularrelationship to the workpiece. Examples of such equipment includecross-cut compound miter saws which are adapted for allowing the user toselectively move the saw blade into any of a number of positions ormodes for square cutting, miter cutting, bevel cutting, or compoundmiter cutting where a combination miter angle and bevel angle are cut.In addition, some operations, such as dado cutting or shapingoperations, for example, require the use of saw blades or other cuttingor working devices of different shapes or sizes to be substituted forone another in order to perform the desired operation on the workpiece,whether the workpiece is composed of wood, plastic, metal or othermaterials.

In order to allow for the adjustment in the miter and the bevel angle,the saw blade, cutter or other working device is angularly adjustablewith respect to a horizontal base and a vertical fence against which theworkpiece is positioned. The miter adjustment allows the saw blade,cutter or other working device to move angularly with respect to thevertical fence while maintaining perpendicularity with the horizontalbase. The bevel adjustment allows the saw blade, cutter or other workingdevice to move angularly with respect to the horizontal base whilemaintaining perpendicularity with the vertical fence. At times it may bedesirable to cut a combination miter angle and bevel angle bysimultaneously adjusting the angularity of the blade with respect toboth the horizontal base and the vertical fence.

Once the saw blade, cutter or other working device has been adjusted tothe desired position with respect to the horizontal base and thevertical fence, locking mechanisms for the miter and bevel adjustmentmust be activated in order to prohibit movement of the saw blade, cutteror other working device with respect to the base and fence while thecutting operation is performed. These locking mechanisms need to beeasily activated, adjustable and quick acting in order to optimize theefficiency of the cutting apparatus and provide convenience to theoperator of the apparatus.

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved bevel lock isemployed in a power tool. The power tool comprises a table. A shaft isdisposed on the table. The power tool also has a support housingsupporting a motor and a working tool driven by the motor. The supporthousing is disposed on the shaft adjacent to the table and is axiallymovable along the shaft and laterally pivotable about an axis ofrotation. In addition, the power tool has a locking mechanism forlocking the support housing at a predetermined lateral position, whereinthe locking mechanism comprises a handle disposed on the shaft. Thehandle is rotatable in two directions with respect to the table, suchthat, upon rotation of the handle on either direction from a neutralposition, the handle urges the support housing into locking contact withthe table.

Other advantages and objects of the present invention will becomeapparent to those skilled in the art from the subsequent detaileddescription, appended claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings which illustrate the best mode presently contemplatedfor carrying out the present invention:

FIG. 1 is a front perspective view of a sliding compound miter saw inaccordance with the present invention;

FIG. 2 is a front elevational view of the sliding compound miter sawshown in FIG. 1;

FIG. 3 is a rear elevational view of the sliding compound miter sawshown in FIGS. 1 and 2;

FIG. 4 is a side elevational view of the sliding compound miter sawshown in FIGS. 1 through 3;

FIG. 5 is an exploded perspective view of a first embodiment of thebevel stop mechanism in accordance with the present invention;

FIG. 6 is an assembled perspective view, partially in cross-section ofthe first embodiment of the bevel stop mechanism shown in FIG. 5;

FIG. 7 is a cross-sectional side view of the first embodiment of thebevel stop mechanism shown in FIG. 5;

FIG. 8 is an end view of the base or table assembly illustrating a firstembodiment of the adjustment feature provided for the bevel stopmechanism shown in FIG. 5;

FIG. 9 is an exploded perspective view of a second embodiment of thebevel stop mechanism in accordance with the present invention;

FIG. 10 is a cross-sectional side view of the second embodiment of thebevel stop mechanism shown in FIG. 9;

FIGS. 11A and 11B are cross-sectional side views of a third and fourthembodiments of the bevel stop mechanism;

FIG. 12 is a cross-sectional rear view along line A—A of FIG. 11B;

FIG. 13 is a top view of the shaft along line B—B of FIG. 12;

FIG. 14 is a cross-sectional side view of a fifth embodiment of thebevel stop mechanism;

FIG. 15 is a cross-sectional rear view along line C—C of FIG. 14;

FIG. 16 is a cross-sectional side view of a sixth embodiment of thebevel stop mechanism;

FIG. 17 is a cross-sectional side view of a seventh embodiment of thebevel stop mechanism;

FIG. 18 is a cross-sectional side view of an eighth embodiment of thebevel stop mechanism; and

FIG. 19 is a cross-sectional side view of a ninth embodiment of thebevel stop mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings in which like reference numerals designatelike or corresponding parts throughout the several views, there is shownin FIGS. 1 through 4 an exemplary sliding compound miter sawincorporating a bevel stop mechanism according to the present invention,shown merely for the purposes of illustration, and designated generallyby the reference numeral 10. One skilled in the art will readilyrecognize from the following description, taken in conjunction with theaccompanying drawings and claims, that the principles of the presentinvention are equally applicable to sliding compound miter saws,compound miter saws, chop saws, radial arm saws, table saws, jigsaws,scroll saws, or other saws of types other than that shown for purposesof illustration in the drawings. Similarly, one skilled in the art willreadily recognize that the principles of the bevel stop mechanismaccording to the present invention are also applicable to other types ofpowered or unpowered equipment for performing an operation on aworkpiece. Such equipment includes, but is not limited to, dado saws,spindle shapers or sanders, or other types of powered or unpowereddevices that would benefit from the cam locking mechanism of the presentinvention.

Referring primarily to FIGS. 1 through 4, sliding compound miter saw 10comprises a base assembly 12, a table assembly 14, a unique housingassembly 16, a saw blade 18, a blade guard 20, a motor 22 drivinglyconnected to saw blade 18, a handle 24 and a fence assembly 26. Tableassembly 14 is secured to base assembly 12 such that it can be rotatedin order to provide adjustment for miter cutting. The rotation of tableassembly 14 changes the angle of saw blade 18 relative to fence assembly26 but maintains the perpendicularity of saw blade 18 with tableassembly 14. A locking mechanism 28 can be activated in order to locktable assembly 14 to base assembly 12.

Housing assembly 16 is secured to table assembly 14 such that it can bepivoted with respect to table assembly 14 in order to provide adjustmentfor bevel cutting. As can be appreciated by one skilled in the art, theadjustments for mitering and beveling can be separate or they can beadjusted simultaneously in order to provide a compound miter and bevelcut. The pivoting of housing assembly 16 changes the angle of saw blade18 relative to table assembly 14 but maintains the perpendicularity ofsaw blade 18 with respect fence assembly 26. A locking mechanism 30 canbe activated in order to lock housing assembly 16 to table assembly 14at any desired bevel angle.

Referring to FIGS. 1 through 5, housing assembly 16 includes supporthousing 32, which mounts a pair of support arms 34 for sliding movementwith respect to housing 32. Saw blade 18, blade guard 20, motor 22 andhandle 24 are all mounted to a drive housing 36 which is pivotablysecured to support arms 34. The pivoting of drive housing 36 downwardtowards table assembly 14 operates to open blade guard 20 and cut aworkpiece which is supported by table assembly 14 and fence assembly 26.The sliding movement of support arm 34 relative to housing 32 permitsdrive housing 36 and thus saw blade 18 to be pulled through theworkpiece when the size of the workpiece exceeds the cutting width ofsaw blade 18.

Referring now to FIGS. 5 through 8, support housing 32 is pivotablysupported with respect to table assembly 14 on a steel shaft 40 which issecured to table assembly 14 and extends rearwardly from table assembly14 to define a pivot axis 42 for support housing 32. Shaft 40 isinserted into a complimentary bore 44 located within table assembly 14and is secured in place using a cross pin 46 which extends through abore 47 extending through shaft 40 and a corresponding set of bores 48located within table assembly, 14 and being generally perpendicular toand extending into bore 44. The end of shaft 40 opposite to the enddefining bore 46 includes a threaded stub 50 for retaining and adjustinglocking mechanism 30 as will be described later herein.

Persons skilled in the art will recognize that the shaft 40 can be fixedto the table assembly 14 using other means. For example, the shaft 40can be soldered or screwed unto the table assembly 14. Similarly, theshaft 40 can be built into the table assembly 14 as a fixed casting.

Locking mechanism 30 comprises a cam 52, a handle 54, a thrust bearing55, a plurality of washers 56 and a locknut 58. Once support housing 32is slidingly and pivotably received on shaft 40, cam 52 is slidinglypositioned on shaft 40 adjacent support housing 32. Cam 52 includes aD-shaped through bore 60 which mates with a corresponding D-shapedportion 62 of shaft 40 such that cam 52 is allowed to move axially alongportion 62 of shaft 40 but rotation of cam 52 with respect to shaft 40is prohibited. Cam 52 further includes an angular camming surface 64having a plurality of ramps which is located on the radial surface ofcam 52 which is opposite to support housing 32. Camming surface 64 isdesigned to mate with handle 54 as will be described later herein.

Handle 54 is slidingly and rotatably positioned on shaft 40 adjacent toand outboard of cam 52. Handle 54 includes an angular camming surface 66having a plurality of ramps which mates with angular camming surface 64on cam 52. Support housing 32, cam 52 and handle 54 are retained onshaft 40 by thrust washer 55, the plurality of washers 56 and locknut 58which is threadingly received on stub 50 of shaft 40.

When angular camming surface 64 and angular camming surface 66 are infull contact with each other as shown in FIG. 7, support housing 32 isfree to pivot on shaft 40 to change the bevel angle of saw blade 18.Once the desired bevel angle has been set, handle 54 is rotated withrespect to shaft 40. Rotation of handle 54 mis-aligns camming surfaces64 and 66 pushing support housing 32 and cam 52 axially along shaft 40.Support housing 32 contacts table assembly 14 and continued rotation ofhandle 54 forces support housing 32 into table assembly 14 locking thetwo components together. The locking of the two components together canbe accomplished by rotating handle 54 in either a clockwise or a counterclockwise direction on order to misalign camming surfaces 64 and 66.This bi-directional locking ability of handle 54 simplifies theadjustment of the bevel angle on opposite sides of center. An indicatorplate 68 is bolted to support housing 32 to allow the user to set aspecific bevel angle. Indicator plate 68 is provided with a pair ofslots which allow for the zero adjustment of plate 68 as is well knownin the art.

Persons skilled in the art will recognize that other camming surfaces onhandle 54 and cam 52 may be provided to obtain the result describedabove. Persons skilled in the art are referred to the parentapplications, which are hereby incorporated by reference.

For example, FIGS. 9 and 10 illustrate a second embodiment of the bevellocking mechanism is illustrated. Unlike the prior embodiment, thehandle 54 is provided with a camming surface 66 a which mates withcamming surface 64 a on cam 52 a. As shown in FIG. 9, the cammingsurface 66 a is provided with peaks 66 p and valleys 66 v. Cammingsurface 64 a has corresponding peaks and valleys in order to mate withcamming surface 66 a. Having the multiple peaks and valleys helps inevenly distributing the camming force. Nevertheless, the arrangement andoperation of the second embodiment is similar to the one illustrated inFIGS. 5 to 7. In addition, the operator is still able to lock thehousing 32 and the table assembly 14 together by rotating handle 54 ineither a clockwise or a counter clockwise direction.

Furthermore, persons skilled in the art will recognize that cam 52 maybe integrated with the support housing 32. This is especiallyadvantageous as less parts are necessary for manufacture, while stillallowing the operator to lock the housing 32 and the table assembly 14together by rotating handle 54 in either a clockwise or a counterclockwise direction.

FIGS. 11A to 13 illustrate a third and fourth embodiments of the bevellock mechanism, where like numerals refer to like parts with likefunctions. In both embodiments the shaft 40 is provided with a “doublescrew” portion 102. As shown in FIG. 13, on one side of the double screwportion 102, a set of threads 101 a are disposed thereon in a firstorientation. In addition, on the other side of the double screw portion102, a second set of threads 101 b are disposed thereon in a secondorientation. The threads 101 a and 101 b intersect to form V-shapedthreads 101. Preferably, the resulting threads 101 will have a lowpitch, so that more travel along the axis of the rod can be obtainedwith a smaller amount of rotation.

The handle 54 a has protrusions 105 to engage the threads 101, as shownin FIG. 14A. These protrusions 105 slide along the threads 101, as thehandle 54 a is rotated, forcing the handle 54 a to travel along shaft40. This in turn forces the handle 54 a towards the support housing 32,thus clamping the support housing 32 in place between handle 54 a andtable assembly 14. Accordingly, the rotational motion of handle 54 a istranslated into a linear motion along shaft 40, causing the clampingaction.

As shown in FIGS. 11A and 11B, the protrusions 105 preferably match theprofile of the threads 101, allowing travel along threads 101.Accordingly if the thread 101 is rounded, the protrusions 105 arepreferably rounded. Persons skilled in the art will neverthelessrecognize that any profile of protrusions 105 will be acceptable so longas the protrusions 105 can slide along the threads 101.

Preferably, the protrusions 105 are disposed on a button 100, as shownin FIG. 11B. It is also advantageous to provide a spring 104 to bias thebutton 100 into contact with the double screw portion 102. Accordingly,in order to install handle 54 a, an operator need only push grippingportion 100 a of the button 100, slide the handle 54 a along the shaft40, and release button 100.

People skilled in the art will recognize that means other than thespring 104 will also allow easy installation and removal of handle 54 a.For example, as shown in FIG. 16, the handle 54 a may include a threadengaging portion 54 b, held in place by a plug 54 c. Accordingly, inorder to install handle 54 a, an operator need only slide the handle 54a along the shaft 40 and insert the thread engaging portion 54 b, sothat it engages the threads 101. The operator can then insert the plug54 c to hold the thread engaging portion 54 b in place.

FIGS. 14 and 15 show yet another embodiment of the bevel lock mechanism.Unlike in the previous embodiments, the locking shaft and the pivot axisare not the same. As shown in FIG. 14, support housing 32 is pivotablysupported with respect to table assembly 14 on a shaft 110 which isfixedly secured to table assembly 14 via threads 111. Persons skilled inthe art will recognize that other means for fixing the shaft 110 to thetable assembly 14 are available. The shaft 110 extends rearwardly fromtable assembly 14 to define a pivot axis 142 for support housing 32.Preferably, the shaft 110 has a threaded portion 112. A thrust bearing551, a washer 561 and a locknut 581 are disposed on the shaft 110 inorder to retain the housing 32.

In addition, locking shaft 401 is inserted into a complimentary bore 441located within table assembly 14 and is secured in place using a crosspin 461 which extends through a bore 471 extending through shaft 401 anda corresponding set of bores 481 located within table assembly 14 andbeing generally perpendicular to and extending into bore 441. The end ofshaft 401 opposite to the end defining bore 461 includes a threaded stub501 for retaining and adjusting a locking mechanism 30, such as the onesdescribed above. As shown in FIG. 14, a slot 140 is provided in thetable assembly 14. The shaft 401 is disposed through the slot 140 sothat, as the bevel angle is changed, the shaft 401 can travel along theslot 140.

Persons skilled in the art will see that the locking shaft 401 issubstantially parallel to shaft 110. However, those persons shouldrecognize that the disclosed embodiment is for exemplary purposes onlyand that the shafts 401 and 110 need not be parallel to each other.

As shown in FIG. 14, the locking mechanism 30 shown in FIGS. 5 to 7 canbe disposed on the locking shaft 401 and used as described above.However, persons skilled in the art will recognize that any of thedifferent embodiments described above for the locking mechanism can beused instead.

FIGS. 17 to 19 illustrate different embodiments of locking mechanism 30.Unlike the previous embodiments, shaft 40 is not fixedly attached to thetable assembly 14. Instead, the shaft 40 is rotatable. In addition, thehandle 54 b is not slidingly and rotatably positioned on shaft 40.Instead, handle 54 b is fixedly attached to or integrated with shaft 40at the outer end of the shaft. Preferably a key 40 k is provided on theshaft 40 to mesh with a groove 54 g in the handle 54 b, or vice versa,to ensure rotational movement of both shaft 40 and handle 54 b. Thus, ifthe operator rotates the handle 54 b, the shaft 40 moves accordingly.

Handle 54 b may be fixedly attached to shaft 40 via a locknut 58.

Furthermore, handle 54 b does not have camming surfaces 66 contactingthe camming surfaces of cam 52′ like prior embodiments. This is becausehandle 54 b does not contact cam 52′ as cam 52′ is not disposed betweenhandle 54 b and the support housing 32. Instead, a cam end 200 isfixedly attached to or integrated with the shaft 40 at its other end, asshown in FIG. 17. Preferably a key 40 kk is provided on the shaft 40 tomesh with a groove 200 g in the cam end 200, or vice versa, to ensurerotational movement of both shaft 40 and cam end 200. Thus, if theoperator rotates the handle 54 b, the shaft 40 and cam end 200 moveaccordingly.

As mentioned above, cam 52′ is not disposed between handle 54 b andsupport housing 32, as in prior embodiments. Instead, cam 52′ isdisposed in table assembly 14 to contact cam end 200. Preferably, cam52′ is integrated with table assembly 14. Cam 52′ preferably does notrotate. Cam 52′ may include an angular camming surface 64′ having aplurality of ramps which is located on the radial surface of cam 52which is nearest cam end 200. Camming surface 64 is designed to matewith a camming surface 200 s on cam end 200 as will be described laterherein.

When angular camming surface 64 and angular camming surface 200 s are infull contact with each other as shown in FIG. 17, support housing 32 isfree to pivot on shaft 40 to change the bevel angle of saw blade 18.Once the desired bevel angle has been set, handle 54 b is rotated.Rotation of handle 54 b (and thus shaft 40 and cam end 200) mis-alignscamming surfaces 64 and 200 s pushing shaft 40 towards table assembly14. Support housing 32 contacts handle 54 b and table assembly 14 andcontinued rotation of handle 54 b forces support housing 32 into tableassembly 14 locking the two components together. The locking of the twocomponents together can be accomplished by rotating handle 54 b ineither a clockwise or a counter clockwise direction on order to misaligncamming surfaces 64 and 200 s. This bi-directional locking ability ofhandle 54 b simplifies the adjustment of the bevel angle on oppositesides of center.

Persons skilled in the art will recognize that the different cammingsurfaces to be used on handle 54 and cam 52 in the different embodimentsdisclosed in the parent applications may also be used on cam end 200 andcam 52′ to obtain the result described above. Again, persons skilled inthe art are referred to the parent applications, which are herebyincorporated by reference.

FIGS. 18 and 19 also illustrate different embodiments of the bevel lockmechanism, where like numerals refer to like parts with like functions.In these embodiments, the shaft 40 is rotatable and handle 54 b isfixedly attached to or integrated with shaft 40 at the outer end of theshaft. Preferably a key 40 k is provided on the shaft 40 to mesh with agroove 54 g in the handle 54 b, or vice versa, to ensure rotationalmovement of both shaft 40 and handle 54 b. Thus, if the operator rotatesthe handle 54 b, the shaft 40 moves accordingly.

A double screw portion 102 is provided at the other end of the shaft 40.Again, as in FIG. 13, on one side of the double screw portion 102, a setof threads 101 a are disposed thereon in a first orientation. Inaddition, on the other side of the double screw portion 102, a secondset of threads 101 b are disposed thereon in a second orientation. Thethreads 101 a and 101 b intersect to form V-shaped threads 101.Preferably, the resulting threads 101 will have a low pitch, so thatmore travel along the axis of the rod can be obtained with a smalleramount of rotation.

The table assembly 14 has protrusions 205 to engage the threads 101, asshown in FIG. 18. These protrusions 205 slide along the threads 101, asthe handle 54 b (and thus shaft 40 and screw portion 102) is rotated,the handle 54 b and shaft 40 travel towards table assembly 14. This inturn forces the handle 54 b towards the support housing 32, thusclamping the support housing 32 in place between handle 54 b and tableassembly 14. Accordingly, the rotational motion of handle 54 a istranslated into a linear motion, causing the clamping action.

As shown in FIGS. 18 and 19, the protrusions 205 preferably match theprofile of the threads 101, allowing travel along threads 101.Accordingly if the thread 101 is rounded, the protrusions 205 arepreferably rounded. Persons skilled in the art will neverthelessrecognize that any profile of protrusions 205 will be acceptable so longas the protrusions 205 can slide along the threads 101.

Preferably, the protrusions 205 are disposed on a thread engagingportion 206, as shown in FIG. 19, held in place by a plug 207.Accordingly, in order to install shaft 40, an operator need only theshaft 40 into the table assembly 14 and insert the thread engagingportion 206, so that it engages the threads 101. The operator can theninsert the plug 207 to hold the thread engaging portion 206 in place.

The above detailed description describes different embodiments of thepresent invention. Persons skilled in the art may recognize otheralternatives to the means disclosed herein, such as using a knob insteadof handle 54. However, all these additions and/or alterations areconsidered to be equivalents of the present invention.

1. A device for performing working operations on a workpiece, saiddevice comprising: a base; a table rotatably disposed on the base abouta substantially vertical axis; a shaft disposed on said table, saidshaft having an axis; a support housing supporting a motor and a workingtool driven by said motor, the working tool being movable about asubstantially horizontal axis between a first position and a lowersecond position, said support housing being disposed on said shaftadjacent to said table, said support housing being axially movable alongsaid shaft and being laterally pivotable about an axis of rotation; anda locking mechanism for locking the support housing at a predeterminedlateral position, wherein said locking mechanism comprises a handledisposed on said shaft, said handle being rotatable in two directionswith respect to said table, such that, upon rotation of said handle inboth directions from a neutral position, the handle urges said supporthousing into contact with said table.
 2. The device according to claim1, wherein the shaft is rotatable relative to the table.
 3. The deviceaccording to claim 2, said locking mechanism further comprises a firstcamming surface disposed on the table.
 4. The device according to claim3, wherein said shaft comprises a second camming surface engaging thefirst camming surface.
 5. The device according to claim 2, wherein theshaft has a first surface having a first thread disposed thereon in afirst orientation, and a second surface having a second thread disposedthereon in a second orientation, said first and second thread intersectforming a V-shaped thread.
 6. The device according to claim 5, whereinthe table comprises at least one protrusion slidable along said firstand second threads.
 7. The device according to claim 1, wherein theshaft axis is substantially parallel to the axis of rotation.
 8. Thedevice according to claim 1, wherein the shaft axis corresponds to theaxis of rotation.
 9. The device according to claim 1, wherein the handleis fixedly disposed on said shaft.
 10. The device according to claim 1,wherein said device is a compound miter saw.